The invention herein relates to metal casting of all types, with particular application to sand casting operations. In this respect, there are basically three basic methods of making sand molds for metal casting. One such method is the damp sand mold utilizing silica, clay, and water with the sand. Such wet sand or green sand methods are used generally for all types of castings, metal or otherwise. On the other hand, dry sand mold casting operations are formed by mixing sand of a rather course grain with a clay bonding material and water, and thereupon baking the mixture to a dry state. The dry sand casting is generally used where heavy pieces of substantial detail are to be cast. Dry sand molds are recommended for steel casting operations as well as many other types. A third type of casting is the modified sand mold, utilizing some of the features of both wet and dry sand casting. Moreover, in all types of casting operations, cores are placed in a casting mold in order to create various internal shaped cavities to receive the molten metal in the process.
Irrespective of the type of casting process utilized, as discussed above, the eventual objective and ideal metal casting is to produce a casting of superior quality, at an economical cost. In order to produce castings of superior quality which are free of imperfections, such as the swells, buckles, and waterleaks, among other possible imperfections, auxiliary support devices must be used to preserve the integrity of the mold and maintain the core in its proper position in the mold cavity. In this respect, especially when cores are used to form hollow spaces in the casting, an auxiliary device, commonly referred to as a chaplet, is used as a support to help maintain the mold cavity intact. More particularly, in any metal casting operation, if there is not adequate chaplet support to maintain the mold cavity there may be resultant defects in the final casting product.
A chaplet is usually a small support structure to provide either horizontal or vertical support in the mold cavity. Some authorities alternately use the term "spacer support" in lieu of chaplet, and this former terminology will be used interchangeably with the word "chaplet" in this application. In this regard, there are several types of chaplets in the prior art. First, there are metallic spacer supports, and primary type used in one which has a vertical stanchion post, fitted with an enlarged circular base on both its upper and lower portion. In brief, such chaplets are formed like a spool, with a severely reduced shank. There are a myriad other types of spacer supports or chaplets too numerous to mention or describe herein; however, the functional purpose of each is basically identical.
The problems with the use of the conventional metal chaplets as discussed above are multifold. First, the main problem with nondisintigratible spacer supports, particularly of the metallic variety, is that of the resultant integrity of the casing. Whenever metal or nondisintigratible chaplets are used, the very presence of a foreign metal which is relatively cold compared to the injected molten metal, leads frequently to a problem of casting weakness at such location. More specifically, one of the major problems encountered in this regard is that when molten metal is injected into the mold cavity, and contact of such molten metal with a portion of a relatively colder metal chaplet, that is exposed to the cavity, causes the molten metal to retract slightly from the metal surface of the chaplet, and there is no resultant bonding between the chaplet and the molten metal. The resultant consequences of such lack of bonding, with a slight retraction of the molten metal at such contact point causes a slight imperfection in the cast product, at this contact point, in the form of an indentation or small defect, and these defects may lead to leakers and othe casting defects. This aspect leads to obvious economic disadvantages in the casting process, and this invention is conceived as a means to overcome this difficulty, and the following objects of the subject invention are directed.